OLC (online config error)

I am trying to establish online config for openLDAP on windows but I am getting this below error how to make online config

5230324d ldif_write_entry: could not put entry file for "cn=config" in place: Invalid argument 5230324d config_build_entry: build "cn=config" failed: "(null)" 5230324d backend_startup_one (type=config, suffix="cn=config"): bi_db_open failed! (-1)

my slapd.conf file

database config rootdn "cn=admin,cn=config" rootPw config

I did slapd test

slapd -T test -f slapd.conf -F slapd.d

waiting for your response

Regards, Pramod